In conventional wireless communication systems, a WTRU can attach to any network regardless of the IP version that the WTRU supports. However, in order to establish IP connectivity, (i.e., PDP context), the IP version of the WTRU must be compatible with the IP version supported by the network. The network may include a Node-B which supports the same IP version as the network.
If the IP versions of the WTRU and the network are not compatible, the PDP context will be rejected, causing the WTRU to be denied IP multimedia subsystem (IMS) based services after a considerable delay period.
For example, the standard, (TS 23.221), mandates that a Third Generation Partnership Project (3GPP) IP Multimedia Subsystem (IMS) exclusively operates according to IP version 6 (v6). However, there will be an IP version 4 (v4) based IMS implementation for GPRS networks, and the 3GPP2 IMS is based on IP v4.
Hence, there is a need for the interworking between different versions of IMSs. A wireless communication method and system for reducing network search time and unnecessary traffic by barring IP incompatible WTRUs from accessing the network is desired.